When to plant Geraniums in Plummer, ID
Plummer's short 146-day growing season means one Geraniums planting between May 15 and May 29. No fall crop in Zone 6b.
When to Plant Geraniums in Plummer, ID
This month in Benewah County, Idaho
July rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Benewah County, Idaho.
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Fire up the seed-starting tray: geraniums
These need a head start before your last frost (May 8). Sow into cells now so you're ready to transplant in a few weeks.
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Bring in the geraniums
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
Coming up in August — start thinking about
- First harvests: geraniums
Geraniums (Pelargonium × hortorum) are tender perennials grown as warm-season annuals throughout North America. Prized for their bold flower clusters, long bloom period, and tolerance of summer heat when planted in well-drained soil, they anchor window boxes, containers, and bed borders from late spring until hard frost. Zones 9b–11b can overwinter plants in the ground.
Plummer, Idaho is in USDA Zone 6b. The average last spring frost is May 8 and the first fall frost is October 1, giving you a growing season of approximately 146 days.
At an elevation of 6,081 feet, Benewah County receives approximately 20.8 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Geraniums during the growing season.
Plummer Soil Profile
Soil Type
Loam
Soil pH
6.3-7.8
Drainage
Well Drained
Geraniums Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Soil Compatibility in Plummer
How your county's soil matches Geraniums's growing requirements.
Soil pH
Your soil pH (6.3–7.8) is more alkaline than Geraniums prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Benewah County is excellent for Geraniums — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.2%). Annual compost additions will help Geraniums.
How to Plant Geraniums
Succession Planting Geraniums
Sow every 8 weeks. Last sowing by Jun 23 to harvest before frost.
Geraniums Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Geraniums
Geraniums needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Geraniums Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 2" | 0" | ❄️ Dormant |
| Apr | — | 2.1" | 0" | ❄️ Dormant |
| May | 4.3" | 2.5" | 1.8" | 💧 Light watering |
| Jun | 4.3" | 1.5" | 2.8" | 🚿 Regular watering |
| Jul | 4.3" | 1.7" | 2.6" | 🚿 Regular watering |
| Aug | 4.3" | 2.2" | 2.1" | 💧 Light watering |
| Sep | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
| Oct | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Nov | — | 1.6" | 0" | ❄️ Dormant |
| Dec | — | 1.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Benewah County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Geraniums Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Geraniums Planting Timeline — Plummer, ID
Geraniums Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 27 | Feb 27 – Mar 13 |
| Transplant Outdoors | May 15 | May 15 – May 29 |
| Bloom | July 24 | Jul 24 – Oct 30 |
Plant 0.1" deep · 12" apart · Rows 14" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors |
| June | — |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 1-2 times/week
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 6b
📆 Growing Season
146 days in Benewah County
Growing Tips for Geraniums in Plummer
Direct sow Geraniums outdoors after May 08 in Benewah County when soil has warmed and frost danger has passed.
Benewah County receives only 21" of rain annually. Geraniums needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Start seeds indoors 10–12 weeks before last frost — germination is slow and erratic without bottom heat (70–75°F). Transplant after frost danger passes. Geraniums rarely direct-sown; cuttings or transplants are the standard. Deadhead spent umbels weekly to maintain continuous bloom. Let soil dry slightly between waterings to prevent root rot. In zones 10–11 plants may be left in ground year-round or overwintered as houseplants.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Geraniums in Other Locations
When should I plant Geraniums in Plummer, ID?
In Plummer, ID, plant Geraniums after the last frost (around May 8) and before the first frost (around October 1). Best results when soil holds above 50°F.
What growing zone is Plummer, ID for Geraniums?
Plummer sits in USDA Zone 6b. Geraniums grows reliably in zones 2a through 11b, so it's a good fit here.
Can Geraniums grow in Plummer's climate?
Yes — Geraniums grows well in Plummer's temperate climate. Plummer averages a 146-day frost-free season, with last frost around May 8 and first frost around October 1.
Your Benewah County Garden Planner — Free
A 22-page printable planner built for Benewah County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.